 /*******************************************************************************
  * Copyright (c) 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui.internal.navigator.filters;

 import java.util.Arrays ;

 import org.eclipse.core.commands.operations.AbstractOperation;
 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IAdaptable;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.jface.viewers.StructuredSelection;
 import org.eclipse.jface.viewers.ViewerFilter;
 import org.eclipse.ui.internal.navigator.CommonNavigatorMessages;
 import org.eclipse.ui.internal.navigator.NavigatorFilterService;
 import org.eclipse.ui.navigator.CommonViewer;
 import org.eclipse.ui.navigator.ICommonFilterDescriptor;
 import org.eclipse.ui.navigator.INavigatorContentService;
 import org.eclipse.ui.navigator.INavigatorFilterService;

 /**
  * Ensures that a given set of filters is <i>active</i> and the complement of
  * that set of filters are not <i>active</i>.
  *
  * <p>
  * This operation is smart enough not to force any change if each id in each set
  * is already in its desired state (<i>active</i> or <i>inactive</i>).
  * </p>
  *
  * @since 3.2
  *
  */
 public class UpdateActiveFiltersOperation extends AbstractOperation {

     private String [] filterIdsToActivate;

     private final CommonViewer commonViewer;

     private final INavigatorContentService contentService;

     private boolean disableTheComplement;

     /**
      * Create an operation to activate extensions and refresh the viewer.
      *
      *
      * @param aCommonViewer
      * The CommonViewer instance to update
      * @param theActiveFilterIds
      * An array of ids that correspond to the filters that should be
      * in the <i>active</i> state after this operation executes. The
      * complement of this set will likewise be in the <i>inactive</i>
      * state after this operation executes.
      * @param toDisableTheComplement True indicates that all filters not in the set should be made inactive.
      */
     public UpdateActiveFiltersOperation(CommonViewer aCommonViewer,
             String [] theActiveFilterIds, boolean toDisableTheComplement) {
         super(
                 CommonNavigatorMessages.UpdateFiltersOperation_Update_CommonViewer_Filter_);
         Assert.isNotNull(theActiveFilterIds);
         
         commonViewer = aCommonViewer;
         contentService = commonViewer.getNavigatorContentService();
         filterIdsToActivate = theActiveFilterIds;
         disableTheComplement = toDisableTheComplement;

     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.commands.operations.AbstractOperation#execute(org.eclipse.core.runtime.IProgressMonitor,
      * org.eclipse.core.runtime.IAdaptable)
      */
     public IStatus execute(IProgressMonitor monitor, IAdaptable info) {

         boolean updateFilterActivation = false;
         
         // we sort the array in order to use Array.binarySearch();
 Arrays.sort(filterIdsToActivate);
         

         try {
             commonViewer.getControl().setRedraw(false);

             INavigatorFilterService filterService = contentService
                     .getFilterService();

             if(disableTheComplement) {
             
                 ICommonFilterDescriptor[] visibleFilterDescriptors = filterService
                         .getVisibleFilterDescriptors();

                 int indexofFilterIdToBeActivated;

                 /* is there a delta? */
                 for (int i = 0; i < visibleFilterDescriptors.length
                         && !updateFilterActivation; i++) {
                     indexofFilterIdToBeActivated = Arrays.binarySearch(
                             filterIdsToActivate, visibleFilterDescriptors[i]
                                     .getId());

                     /*
                      * Either we have a filter that should be active that isn't
                      * XOR a filter that shouldn't be active that is currently
                      */
                     if (indexofFilterIdToBeActivated >= 0
                             ^ filterService
                                     .isActive(visibleFilterDescriptors[i]
                                             .getId())) {
                         updateFilterActivation = true;
                     }
                 }

                 /* If so, update */
                 if (updateFilterActivation) {

                     filterService.setActiveFilterIds(filterIdsToActivate);
                     filterService.persistFilterActivationState();

                     commonViewer.resetFilters();

                     ViewerFilter[] visibleFilters = filterService
                             .getVisibleFilters(true);
                     for (int i = 0; i < visibleFilters.length; i++) {
                         commonViewer.addFilter(visibleFilters[i]);
                     }

                     // the action providers may no longer be enabled, so we
 // reset the selection.
 commonViewer.setSelection(StructuredSelection.EMPTY);
                 }
             } else {
                 NavigatorFilterService internalFilterService = (NavigatorFilterService)filterService;
                 
                 internalFilterService.addActiveFilterIds(filterIdsToActivate);

                 ICommonFilterDescriptor[] visibleDescriptors = filterService
                         .getVisibleFilterDescriptors();
                 for (int i = 0; i < visibleDescriptors.length; i++) {
                     if(Arrays.binarySearch(filterIdsToActivate, visibleDescriptors[i].getId()) >= 0 ) {
                         commonViewer.addFilter(internalFilterService.getViewerFilter(visibleDescriptors[i]));
                     }
                 }

                 // the action providers may no longer be enabled, so we
 // reset the selection.
 commonViewer.setSelection(StructuredSelection.EMPTY);
             }

         } finally {
             commonViewer.getControl().setRedraw(true);
         }
         return Status.OK_STATUS;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.commands.operations.AbstractOperation#redo(org.eclipse.core.runtime.IProgressMonitor,
      * org.eclipse.core.runtime.IAdaptable)
      */
     public IStatus redo(IProgressMonitor monitor, IAdaptable info) {
         return null;
     }

     /*
      * (non-Javadoc)
      *
      * @see org.eclipse.core.commands.operations.AbstractOperation#undo(org.eclipse.core.runtime.IProgressMonitor,
      * org.eclipse.core.runtime.IAdaptable)
      */
     public IStatus undo(IProgressMonitor monitor, IAdaptable info) {
         return null;
     }
 }

